I agree with you about the combat mechanisms, a little more details ( and explanations about what is happening ) would be more immersive for the player. A system with opposing counters on the front line would be cool too ( who fights who ) with cavalry on the side, heavy infantry in the center, effects of a reserve, adequate bonuses for overrunning, etc, etc ...
I also agree with you with representation of the Spanish theater, but I think that it's a result of the overall scale choice. 5 provinces in Italy seems very few too, on the same subject.
I was thinking about something else too. I read in your forum that you states your project is a little over-ambitious for a single man, and I agree with that ( main reason of time delay ). I also read that you were searching a games' studio and found difficult to associate with one that has the same ambitions of making a good and complex game on this Era. I modestly think that Ageod perfectly fits with what you're searching for. Furthermore, Philippe Thibaut has some very good experiences with the subject, as he was the game's developper of Pax Romana in the beginning of the decade. I know that you consider your project as your "little baby"

, and that it's difficult to make concessions with other persons about your ideas and ways of making things, but as the first buyer of such a game if, by luck, it is released one day

, I think that an association with the Age studio will allow you to have ressources that you may have great usefulness. I don't know if you have already try to contact them, or if you have some personnal reasons to not do that ( things that I can understand ), but I think that it could be a very good thing, profitable for everybody.
I hope that I don't embarass anybody with such a statement, but I was thinking of that from a player point of vue and write what I have in mind.
Cheers,
Math.